There are contact assemblies that couple stationary terminals to moving terminals which assemblies are used where there is relative movement between terminals. In applications where the relative movement between the stationary and moving terminals is rotational, brush contacts are commonly used to maintain an electrical connection. In such rotational applications the gap between the two terminals remains constant even though one terminal is stationary and the other terminal is moving. The brush contacts, often called bank-and-wiper contacts or rotary contacts, bridge the gap between terminals utilizing a conductive element such as a flexible copper finger that extends from one terminal conductively contacting the opposing terminal. During rotational movement the flexible copper finger wipes across the surface of the opposing terminal completing the electric circuit.
During manufacturing, many mass produced products are fabricated and/or tested utilizing automated or semi-automated equipment. It is commonplace for such automated equipment to include revolving platforms that guide products through various assembly or testing procedures. If it is necessary to couple the manufactured product to a power source or test lead, while positioned on the revolving table, brush contacts are often used.
Tradition brush contacts work by wiping action wherein the finger of the contact directly abuts against an opposing terminal as it rotates. The wiping action of the contacts create a great amount of wear on both the finger and surface. Excessive wear results in the need to readjust the finger or its contact surface to compensate for the wear and ensure a proper electrical contact. Similarly, the excessive wear causes debris which contaminates the area of the brush contact. The debris may cause electrical shorts, jam sensitive mechanical movements and require excessive preventative maintenance process.
The fingers of traditional brush contacts in rotary applications are formed so as to operate with only one direction of rotation. This is especially true on rotating tables, and other platforms, where the platform is designed to rotate in only one direction. However, rotating platforms sometimes jam or otherwise require attention. In such situations, it is possible, if not desirable, to rotate the platform in a direction opposite its normal mode of operation. Such a manipulation may help to unjam the machine, but the reverse rotation can bend and destroy traditional brush contacts. The damaged contact then needs to be replaced or repaired before the rotating platform can again function properly.
It is therefore a primary objective of the present invention to provide a contact assembly that can be used in place of traditional brush contacts that couple a rotating terminal to a stationary terminal with reduced wear, debris caused by wear, and the need for readjustment.
It is an additional object of the present invention to provide a contact assembly that is not dependent on the direction of rotation between terminals.